Evaluation of the strength parameters of clay loams during freezing–thawing cycles

Abstract

Destructuring settlements due to frost heave during the structures’ exploitation are often not taken into account at the designing stage, although they are indirectly related to the bearing capacity of the soils. The objective of this research was analyzing the effect of the number of freezing–thawing cycles on the strength characteristics of soils. Tests of the clay loams with void ratio e = 0.55 and with various initial parameters (initial moisture content, and the number of freezing–thawing cycles) was carried out. According to the experimental results, the cohesion largely depends on the above parameters which might lead to its decrease by up to 5 or 6 times. The internal friction angle demonstrated an indefinite behavior during the freeze-thaw cycles, which is confirmed by a literature review. Changes in strength parameters of the soil during freezing–thawing cycles can lead to significantly decreasing of the soil bearing capacity. A program based on the least-squares method was used to calculate the approximation coefficients of the dependence describing the changes in strength characteristics from the abovementioned parameters. Changes in strength characteristics must be taken into account when designing structures, as they can lead to additional settlement or even subsidence of the foundations.